Gmail is very specific when it comes to deleting vs. archiving in mail clients such as Outlook. When a message is “expunged” in Outlook, the default Gmail action is to archive it (so it still shows up in All Mail) rather than deleting it. You can change this behavior in Gmail itself.
- Go to Gmail’s settings (or via this link).
- In the IMAP Access section, select the following options:
- When I mark a message in IMAP as deleted:
Auto-Expunge off – Wait for the client to update the server.
- When a message is marked as deleted and expunged from the last visible IMAP folder:
Move the message to the Trash
I had no idea that Gmail is this particular…